prime numbers
public class Prime {
public static void main(String[] args) {
int num = 29;
boolean flag = false;
for(int i = 2; i <= num/2; ++i){
if(num % i == 0){
flag = true;
break;
}
}
if (!flag)
System.out.println(num + " is a prime number.");
else
System.out.println(num + " is not a prime number.");
}}